Sun­day, Nov. 11, marks the 100th an­niver­sary of the end of World War I. The guns fell silent in Eu­rope at the 11th hour of the 11th day of the 11th month of the year. As word spread that the Great War was over, spon­ta­neous cel­e­bra­tions broke out. New York­ers awoke to sirens and fac­tory whis­tles an­nounc­ing war’s end. The Bri­tish press re­ported that women in Lon­don “wore their hair down and gave out kisses gen­er­ously.”

There had never been a con­flict like it. An es­ti­mated 20 mil­lion or more died, mil­i­tary and civil­ians. It was sup­posed to be “the war to end all wars,” but the ex­u­ber­ance would not last.

The lead­ers of 32 coun­tries met out­side Paris in early 1919 and pro­duced the Treaty of Ver­sailles, set­ting forth the peace terms. Ger­many, de­feated in the war and not given a seat at the ta­ble in Ver­sailles, was forced to ac­cept re­spon­si­bil­ity for start­ing the war, saw its mil­i­tary dras­ti­cally re­duced and was made to pay repa­ra­tions to the Al­lies.

Bri­tish prime min­is­ter David Lloyd Ge­orge thought the treaty was too harsh and pre­dicted: “We shall have to fight an­other war again in 25 years’ time.” It didn’t even take that long.

Af­ter fall­ing be­hind in its pay­ments, the Ger­man gov­ern­ment be­gan print­ing more money, set­ting off mas­sive in­fla­tion. As Ger­mans saw their pur­chas­ing power drop, na­tion­al­ists in the coun­try fanned re­sent­ment by pro­mot­ing the idea that Ger­many was shoul­der­ing un­fair blame for the war. Those forces co­a­lesced into Adolph Hitler’s Nazi party, which led to an­other world war, one with far more ca­su­al­ties.

It’s his­tory and it’s a warn­ing, as na­tion­al­ism rises again, here and around the world.

In 1954, in the af­ter­math of World War II and the Korean War, the United States changed the name of Ar­mistice Day to Vet­er­ans Day, to honor all U.S. mil­i­tary per­son­nel, whether they served in war or peace. We re­mem­ber them all on this Vet­er­ans Day, but es­pe­cially those who served in World War I.

The cer­e­monies are fit­tingly solemn now. In­spired by a fa­mous poem, red pop­pies will be worn around the world, a sym­bol of the war. A Cana­dian doc­tor, Lt. Col. John McCrae wrote “In Flan­ders Fields” af­ter see­ing a young Cana­dian sol­dier killed by a Ger­man ar­tillery shell.

The open­ing verse im­mor­tal­ized the poppy as a sym­bol of war re­mem­brance:

Pres­i­dent Trump will join French Pres­i­dent Em­manuel Macron and some 70 other world lead­ers at a cer­e­mony Sun­day at the Arc de Tri­om­phe in Paris, mark­ing the cen­te­nary. He’s also sched­uled to visit sev­eral memo­rial sites ded­i­cated to Amer­i­can ser­vice mem­bers.

The pres­i­dent will not at­tend a “peace fo­rum” or­ga­nized by Macron for Sun­day, a sign of con­tin­u­ing ten­sion be­tween the two lead­ers.

Macron this week toured wartime bat­tle­fields in France and warned of on­go­ing threats to Eu­rope, say­ing the con­ti­nent needs its own army.

“We need to pro­tect our­selves from China, from Rus­sia and even the United States,” Macron told France’s Eu­rope 1 ra­dio sta­tion.

Other lead­ers at the peace fo­rum will no doubt be try­ing to score po­lit­i­cal points at Trump’s ex­pense, but the sym­bol­ism of the U.S. pres­i­dent stand­ing with other coun­tries to com­mem­o­rate the end of the war should not be lost on the world.

Shared mo­ments of si­lence and the plac­ing of wreaths on grave sites are sober­ing re­minders of the toll of war, and can be uni­fy­ing sym­bols for na­tions will­ing to cel­e­brate their shared sac­ri­fices rather than fo­cus on what keeps them apart.